In one convention system, a host CPU in a host executes a host OS. The OS performs (alone and/or in combination with other software executed by the CPU) security features. These features are intended (ideally) to prevent an unauthorized user (or malicious software attempting to pose as an authorized user) from issuing unauthorized commands to or otherwise compromising the host. In actual implementation, however, such software-based security features suffer from significant disadvantages and drawbacks that may prevent the software from achieving these ideally intended results.
For example, such software-based security features are incapable of ensuring that it is an actual user (and not, for example, malicious software posing, either locally or remotely via a network, as a user) that is seeking access to the host. Additionally, such software-based security features tend to be relatively easily infiltrated, corrupted, and/or circumvented by malicious software (e.g., as compared to security features that are implemented predominately or entirely in hardware or firmware).
One proposed solution involves including trusted platform module (TPM) security hardware in the host. Such TPM hardware may comply with TPM Main Specification (including Part 1 Design Principles, Part 2 TPM Structures, and Part 3 Commands), Version 1.2, Revision 116, published 1 Mar. 2011, by Trusted Computing Group, Inc. The TPM hardware is exposed to a trusted hardware attestation key device via a user physical presence general purpose input/output (GPIO) pin of TPM hardware. The pin is set when a user physically presses a certain button of the host. The setting of the pin grants the user (i.e., the person who pressed the button) access to the security functions of the TPM hardware.
Unfortunately, in this conventional arrangement, no separate authentication (e.g., independent of the user merely pressing the button) of the user is involved prior to, and as a condition for, the user being granted access to the security functions of the TPM. Accordingly, if an unauthorized user obtains physical access to the host and presses the button, the unauthorized user is granted access to the security functions of the TPM hardware.
Also, in this conventional arrangement, continuing access to the security functions of the TPM hardware is not conditioned upon an authorized user remaining in proximity to the host. Accordingly, such access may not be revoked even if the user ceases to be in proximity to the host. Unfortunately, this may permit an unauthorized person to gain access to such functions, for example, after the authorized user has left the proximity of the host.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly.